TY - JOUR
T1 - Muscle compensation strategies to maintain glenohumeral joint stability with increased rotator cuff tear severity
T2 - A simulation study
AU - Khandare, Sujata
AU - Arce, Richard A.
AU - Vidt, Meghan E.
N1 - Funding Information:
Financial support was provided by start-up funds from The Pennsylvania State University (Vidt), USA , and a travel award to the OpenSim Advanced User Workshop from the NIH National Center for Simulation in Rehabilitation Research (NCSRR) .
Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2022/2
Y1 - 2022/2
N2 - Rotator cuff tear (RCT) in older adults may cause decreased muscle forces and disrupt the force balance at the glenohumeral joint, compromising joint stability. Our objective was to identify how increased RCT severity affects glenohumeral joint loading and muscle activation patterns using a computational model. Muscle volume measurements were used to scale a nominal upper limb model's peak isometric muscle forces to represent force-generating characteristics of an average older adult male. Increased RCT severity was represented by systematically decreasing peak isometric muscle forces of supraspinatus, infraspinatus, and subscapularis. Five static postures in both scapular and frontal planes were evaluated. Results revealed that in both scapular and frontal planes, the peak glenohumeral joint contact force magnitude remained relatively consistent across increased RCT severity (average 1.5% and −4.2% change, respectively), and a relative balance of the transverse force couple is maintained even in massive RCT models. Predicted muscle activations of intact muscles, like teres minor, increased (average 5–30% and 4–17% in scapular and frontal planes, respectively) with greater RCT severity. This suggests that the system is prioritizing glenohumeral joint stability, even with severe RCT, and that unaffected muscles play a compensatory role to help stabilize the joint.
AB - Rotator cuff tear (RCT) in older adults may cause decreased muscle forces and disrupt the force balance at the glenohumeral joint, compromising joint stability. Our objective was to identify how increased RCT severity affects glenohumeral joint loading and muscle activation patterns using a computational model. Muscle volume measurements were used to scale a nominal upper limb model's peak isometric muscle forces to represent force-generating characteristics of an average older adult male. Increased RCT severity was represented by systematically decreasing peak isometric muscle forces of supraspinatus, infraspinatus, and subscapularis. Five static postures in both scapular and frontal planes were evaluated. Results revealed that in both scapular and frontal planes, the peak glenohumeral joint contact force magnitude remained relatively consistent across increased RCT severity (average 1.5% and −4.2% change, respectively), and a relative balance of the transverse force couple is maintained even in massive RCT models. Predicted muscle activations of intact muscles, like teres minor, increased (average 5–30% and 4–17% in scapular and frontal planes, respectively) with greater RCT severity. This suggests that the system is prioritizing glenohumeral joint stability, even with severe RCT, and that unaffected muscles play a compensatory role to help stabilize the joint.
UR - http://www.scopus.com/inward/record.url?scp=85068893396&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85068893396&partnerID=8YFLogxK
U2 - 10.1016/j.jelekin.2019.07.005
DO - 10.1016/j.jelekin.2019.07.005
M3 - Article
C2 - 31324511
AN - SCOPUS:85068893396
SN - 1050-6411
VL - 62
JO - Journal of Electromyography and Kinesiology
JF - Journal of Electromyography and Kinesiology
M1 - 102335
ER -